Yeah, saw this article. They say the best reasoning for the failure would be a botched re-installation by some goon after fiddling with the car past its assembly finish point. That seems like the only plausible idea imo, considering this never happens in road tests.

Quote:

Ford reacted instantly to news of the failure. Our Boss 302 was collected and sent away for a tear-down and inspection. The Mustang line was shut down, and every brake assembly checked. Ford also reviewed its process to ensure incorrect attachment of the brake pedal arm to the master cylinder clevis rod end could not occur. We’re told no anomalies were found. And we haven’t seen anything awry on the Mustangs we’ve checked since.
How the arm was misassembled on our Boss 302 tester remains a mystery to Ford, and to us. The only thing we can think of is this particular car’s master cylinder had been removed after it left the factory, and the incorrect connection to the brake pedal arm made when it was reinstalled, although we have no proof either way. Based on the evidence, we’re prepared to chalk this incident up to a freakish combination of circumstances.